So what you're advocating is for utilities to be held liable for their customers' use of their product? Or held liable for the what their customers' actions are as a result of the utilities' purpose?
No quite the opposite. Utilities are not held responsible for their users' behavior specifically because they're public utilities, and are therefore subject to extreme regulatory constraints.
On the other hand if I own a house and my tenant, without my knowledge, is selling drugs out of the house, then the government can hold me liable to some extent, depending on the circumstances. My house is not public, and I am responsible for what people do in it.
FB, Google, Twitter, et al. want it both ways. They want no regulatory oversight, and they want to never be held accountable for what is done with their products. I happen to find that disagreeable.